We model the odd-proton nucleus ${}^{223}\mathrm{Ac}$ as a ${}^{208}{\mathrm{P}\mathrm{b}+}^{14}\mathrm{C}+p$ system. The odd proton occupies ${0h}_{9/2},$ ${1f}_{7/2},$ and ${0i}_{13/2}$ states with energies taken from the known spectrum of ${}^{209}\mathrm{Bi},$ while the ${}^{14}\mathrm{C}$ cluster occupies $0^{+},$ $2^{+},$ $4^{+},\dots ,$ and $1^{-},$ $3^{-},$ $5^{-},\dots ,$ states, relative to ${}^{208}\mathrm{Pb},$ whose energies are taken from the known levels of ${}^{222}\mathrm{Ra}.$ The ${}^{14}\mathrm{C}-p$ interaction mixes together the various combinations of proton and ${}^{14}\mathrm{C}$ orbital motion states coupled to total angular momentum I. The Pauli principle is satisfied by excluding the odd proton from orbitals above the ${}^{208}\mathrm{Pb}$ Fermi surface already occupied by protons in the ${}^{14}\mathrm{C}$ cluster. We predict low-lying parity doublet bands with $K^{\pi }$ values ${\frac{5}{2}}^{\pm }$ and ${\frac{3}{2}}^{\pm },$ in agreement with observation.

We calculate the cross sections for dissociation of $J/\psi$ by pions and ρ mesons within the framework of a meson exchange model. We find that these cross sections are small at center-of-mass energies less than 1 GeV above threshold, and that dissociation rates are less than $0.01\mathrm{fm}/c$ in a thermal meson gas at temperatures where such a description makes sense.

The high spin states in the N=81 odd-odd ${}^{142}\mathrm{Pm}$ have been investigated by in-beam γ-spectroscopy following the reaction ${}^{133}\mathrm{Cs}{(}^{13}\mathrm{C}{,4n)}^{142}\mathrm{Pm}$ at E=63 MeV and using a gamma detector array. Thirty new $\gamma$ rays have been assigned to ${}^{142}\mathrm{Pm}$ on the basis of the $\gamma$-ray singles and $\gamma$-$\gamma$ coincidence data. The level scheme of ${}^{142}\mathrm{Pm}$ has been extended considerably above the known 2 ms isomer at 883.0 keV and spin-parity assignments for several levels have been made. The proposed level structure is discussed in the light of available data for the neighboring odd-odd isotones.

We explore approximations to the effective S factor for the ${}^7\mathrm{Be}(p,\gamma {)}^8\mathrm{B}$ reaction using different approximations for the integral over the Gamow peak. In the temperature range of interest for solar neutrino production, $S_{\mathrm{eff}}$ may be determined to within 0.5% from $S\left(20\right)\mathrm{}$ with no direct information on the derivatives of $S\left(E\right).$

We calculate the nuclear level density parameter a for a broad range of temperatures $(0.6\mathrm{}<~T<~6\hspace{0.5em}\mathrm{MeV})$ using a microscopic model which includes important ingredients like the thermal and quantal fluctuations of nuclear shapes, continuum corrections, and Coulomb interaction. Numerical calculations have been performed for ${}^{40}\mathrm{Ca}$ and ${}^{56}\mathrm{Fe}$ in a large model space. We find that at low temperatures, shell effects are larger for ${}^{40}\mathrm{Ca}$ and effects of quantal fluctuations are larger for ${}^{56}\mathrm{Fe}.$ As temperature increases, these effects tend to disappear and continuum corrections become important for $T>\mathrm{}3\mathrm{}\hspace{0.5em}\mathrm{MeV}.$

A general formalism to discuss the role of noncentral forces in reactions with arbitrary spins is outlined. The formalism is applied to the particular case of $\Delta$ excitation in inelastic nucleon-nucleon scattering.

High-spin states in the odd-odd $N=Z$ nucleus ${}^{50}\mathrm{Mn}$ have been identified. At low spin, the $T=1\mathrm{}$ isobaric analogue states of ${}^{50}\mathrm{Cr}$ are established up to $I^{\pi }{=4\mathrm{}}^{+}.$ At high spin, the $T=0\mathrm{}$ band built on the low-lying $I^{\pi }{=5\mathrm{}}^{+}$ isomer in ${}^{50}\mathrm{Mn}$ becomes energetically favored and this band is observed up to its $f_{7/2}$-shell termination at $I^{\pi }{=15\mathrm{}}^{+}.$ Spherical shell model calculations in the full $\mathrm{pf}$ shell are found to be in excellent agreement with the experimental results. In addition, a weak side band in ${}^{50}\mathrm{Mn}$ is observed to spin ${(12\mathrm{}}^{-})$ and is interpreted as a possible octupole vibrational structure.

The near-drip-line nucleus ${}^{127}$Pr was populated with the reaction ${}^{92}$Mo${(}^{40}$Ca,$\alpha p)$ at a beam energy of 175 $\mathrm{Me}$V. Particle-$\gamma$-$\gamma$ coincidences were collected, and the total energy plane gating technique was used to enhance events associated with the $\alpha p$ exit channel. This enabled two new rotational bands to be assigned to ${}^{127}$Pr, including a strongly coupled structure. Its similarity with analogous bands in heavier Pr isotopes suggests this structure is most likely based on a hole in the extruder $\left[404\right]{9/2}^{+}$proton orbital. The occupancy of this orbital is associated with enhanced quadrupole deformation in this mass region.

An experiment designed to populate two-phonon vibrational states in ${}^{208}\mathrm{Pb}$ by Coulomb excitation was performed with a ${}^{136}\mathrm{Xe}$ beam at a bombarding energy of 650 MeV. The γ rays from the decay of the excited states were measured with Gammasphere and scattered particles were detected in the compact heavy-ion counter CHICO. We have not been able to observe any state close to the expected harmonic energy of 5.2 MeV. However, we were able to extract the ${B(E3,3\mathrm{}}_1^{-}\to 6_1^{+})$ value for the lowest known $6^{+}$ state at 4.424 MeV based on measured γ-ray intensities. About 20% of the expected total $E3\mathrm{}$ strength can be found in this state, suggesting a large fragmentation of this second octupole phonon state in ${}^{208}\mathrm{Pb}.$ Upper limits for the $B\left(E3\mathrm{}\right)\mathrm{}$ strength were determined for higher-lying, but unseen, $6^{+}$ states ranging from 15% of the harmonic value at 5.2 MeV to 100% at 6.0 MeV.

Ratios of the populations of ground and excited states of ${}^4\mathrm{He},$ ${}^5\mathrm{Li},$ and ${}^8\mathrm{Be}$ and double ratios constructed from the yields ${}^{3,4}\mathrm{He},$ ${}^{6,7,8}\mathrm{Li},$ ${}^{11,12,13}\mathrm{C}$ isotopes were measured for central Kr+Nb collisions at $E/A=35,\hspace{0.5em}70,\hspace{0.5em}100,$ and 120 MeV. These ratios were analyzed to estimate an apparent temperature for emission. Consistent and approximately constant apparent temperatures were obtained from the excited states of ${}^4\mathrm{He},$ ${}^5\mathrm{Li},$ and ${}^8\mathrm{Be}$ nuclei and from thermometers based upon the yields of carbon isotopes. In contrast, apparent temperatures obtained from thermometers based upon the ratios using helium isotopes increase monotonically with incident energy.

The average g factors of the high-energy states of the three superdeformed bands in ${}^{194}\mathrm{Hg}$ were determined directly in a transient field experiment. The reaction ${}^{150}\mathrm{Nd}{(}^{48}\mathrm{Ca}{,4n)}^{194}\mathrm{Hg}$ at a beam energy of 203 MeV was used to provide recoiling reaction product nuclei with sufficient velocity to traverse a gadolinium ferromagnetic layer. The resulting g factors $g\left(\mathrm{SD}1\mathrm{}\right)=0.36\mathrm{}\left(10\right),$ $g\left(\mathrm{SD}2\mathrm{}\right)=0.41\mathrm{}\left(20\right),$ and $g\left(\mathrm{SD}3\mathrm{}\right)=0.71\mathrm{}\left(26\right)\mathrm{}$ are in agreement with cranked Hartree-Fock calculations as well as with the picture of a rigid rotation for which $g=Z/A.\mathrm{}$

Two superdeformed bands of 10 transitions each have been found in ${}^{189}\mathrm{Tl}$ extending the mass 190 region of superdeformation down to neutron number $N=108.\mathrm{}$ The new bands can be interpreted as signature partners and are proposed to be based on a proton $i_{13/2}$ $(\Omega =5/2)$ configuration, in analogy with the yrast superdeformed band structures in the heavier odd-mass Tl isotopes. The dynamic moments of inertia of all these bands show no noticeable differences as function of $N,$ consistent with an essentially constant quadrupole deformation from the center of the island to its edges.

Results are presented of a systematic survey of $\Delta I=4\mathrm{}$ bifurcation in 19 superdeformed bands in $A\sim 150$ Eu and Gd nuclei. The majority of bands show no sign of this regular oscillation in energy levels. The statistical significance of the few examples that exhibit the effect is examined.

We use the three-body model and the sudden approximation to compute angular correlations in high-energy fragmentation reactions of two-neutron halos on light targets. The contribution from one-neutron absorption by far dominates over that of neutron scattering. We use ${}^6\mathrm{He}$ $(n+n+\alpha )$ and ${}^{11}\mathrm{Li}$ ${(n+n+}^9\mathrm{Li})$ as examples and study the dependence of the predictions of this model on different physical assumptions and parameters.

We have performed molecular dynamics calculations and employed early cluster recognition algorithms to identify the number, positions, and velocities of the IMFs. The fragmentation pattern may be identified quite early in the expansion following the collision, well before thermalization. The IMFs appear throughout the volume of the system, and not concentrated on any particular region.

A new Nilsson single-particle structure is proposed for neutron-rich nuclei near ${}^{132}\mathrm{Sn}$. In general, a large reduction in spin-orbit interaction is required and the neutron $N=82\mathrm{}$ gap persists in the new set of parameters. The ground state deformations for several isotopic chains are studied with this set and compared with the results of the standard set and with measured ones. Collective bands in two even-even, neutron-rich nuclei are calculated using the projected shell model with the new set of parameters and improved agreement with existing data is found.

We have measured the $\mathrm{pp}$ spin correlation coefficients $A_{\mathrm{xx}},$ $A_{\mathrm{yy}},$ $A_{\mathrm{xz}}$ and the analyzing power $A_y$ at 250.0, 280.0, 294.4, 310.0, 350.0, 399.1, and 448.9 MeV over the laboratory angular range $3.5°–43.5°$ $({\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=7\mathrm{}°–90°).\mathrm{}$ The statistical accuracy is approximately $\pm 0.006$ for $A_y$ and $\pm 0.02$ for $A_{\mathrm{mn}}$ per $1°$ angle bin, while the corresponding scale factor uncertainties are 1.3 and 2.5 %, respectively. The experiment makes use of a polarized hydrogen gas target internal to a proton storage ring (IUCF Cooler) and a circulating beam of polarized protons. The method of calibration relative to pp spin correlation coefficients and analyzing power at 197.4 MeV, the injection energy, involves up and down ramping of the energy of the polarized beam. The data are compared to recent $\mathrm{pp}$ partial waves analyses and $\mathrm{NN}$ potential models, emphasizing in particular the energy dependence in the region of the pion production threshold.